• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Why new motor mounts?

W

W30post

New member
Guys, I see lots of people on the W-bodys change the lower engine and trans mounts. My Monte Carlo has 85K on it. The trans shop that is trying to help find a bounce out of the car says the mounts "look" great. Other than just the fluid showing a mess and maybe the mount squished out why are you guys changing them?

My car has new axles with less than 300 miles, new wheel bearings less than 5K miles and new tires less than 3K miles that were road force balanced. The issue comes and goes but is a lot worse lately. I saw one post on here the lower mounts were neednig to be changed on his at 61K miles.

I know mounts are cheap but have you guys seen a difference in the ride of the car when the mounts have been changed? Does changign to the rubber instead of the fluid filled show any improvement?

Thanks for any help.
 


We change them when they are clunking, leaking and generally fubared.

Here's an example of one that needs to be changed
IMG_20120423_172613.jpg
 
Maybe.. The motor mount in the bucket is often soaked in oil etc and over time that degrades it and presto...it fails like ZZP.
 
If your mount is squished...

Or if there is a obvious sign of fluid that has puked from it...

Then yes, they need replaced...or another tall tale sign is looking at your motor from the top of the engine bay...does it look like its leaning to one side? One side...say, the left side lower than the right?

Mounts are a great way to improve driveability and better traction/power transfer/feedback to the driver...I'd opt for the solid rubber replacements, and ditch thinking about putting some factory fluid filled ones back in...because...they will do just what the ones you have in there now are doing...FAIL.

To add, click the link in my signature...there is a free mod called the "Dog Bone Flip"...look into it...that'll help as well when you put the new lower mounts in to take some strain off of them and increase the life of them by quite a bit.
 


bluegtp91 said:
If your mount is squished...

Or if there is a obvious sign of fluid that has puked from it...

Then yes, they need replaced...or another tall tale sign is looking at your motor from the top of the engine bay...does it look like its leaning to one side? One side...say, the left side lower than the right?

Mounts are a great way to improve driveability and better traction/power transfer/feedback to the driver...I'd opt for the solid rubber replacements, and ditch thinking about putting some factory fluid filled ones back in...because...they will do just what the ones you have in there now are doing...FAIL.

To add, click the link in my signature...there is a free mod called the "Dog Bone Flip"...look into it...that'll help as well when you put the new lower mounts in to take some strain off of them and increase the life of them by quite a bit.
Click to expand...

The trans shop that has been looking over a slow body oscillation/vibration claimed the mounts looked great. I was just asking if the fuild had leaked and the car got cleaned before I bought it what would I feel if they had leaked. The bottom of this car looks almost new it is that clean with 85K miles now..

They are putting in solid rubber moutns in the morning. I will flip the upper dog bone mounts tomorrow when I get the car home. This is a stock 04 Monte Carlo SS SC car that has been to the track a couple times.
 
My gtp has had a come and go vibration ever since i got it, i have only put about 3000 miles on it. I just put centric premium rotors on and bam noooooo vibration at all its like new. Just a thought.
 
SLICK98 said:
My gtp has had a come and go vibration ever since i got it, i have only put about 3000 miles on it. I just put centric premium rotors on and bam noooooo vibration at all its like new. Just a thought.
Click to expand...



Even while you foot is off the brakes? Mine is not so much a vibration as a bounce. We have another car that I bought that was still for four years. My Monte Carlo has almost the same frequency of oscillation as the car with 4 year flat spotted tires.

Just wondering if the bounce in the seat is from the motor moving around too much. Will know more tonight I guess.
 
Last edited:
OK, motor mounts changed to solid rubber mounts. I flipped the radiator support mounts also. I can tell a difference in the vehicle dynamics but the original problem I am chasing is still there.

Now what next? Is it the 25 lbs of road force bouncing the car around?
 


This is a very helpful thread for me! I also have the bounce/clunk. I can see my engine leaning more to one side. Is the motor mount hard to change? I'll be checking my struts tomorrow too!
 
TLSheff said:
Next I would look into this, just as an option of where to start. Clunks can be all sorts of things, I have to inspect my car for one it started about a month ago... tech said it could me a mount (motor/tranny or front strut) or it could be the intermediate shaft. but start with the easy one.
9186d1337058541-what-why-like-what-should-i-do-pic-2012-05-13-19.28.05.jpg

Red circle... does yours look worn like this???

http://www.grandprixforums.net/what-why-like-what-should-i-do-pic-62788.html
Click to expand...

I will have to look today but I have not noticed anything like this. I do have the intermediate shaft clunk sometimes but I know what that feels like and how to reduce it for a while..
 
mrfreez said:
This is a very helpful thread for me! I also have the bounce/clunk. I can see my engine leaning more to one side. Is the motor mount hard to change? I'll be checking my struts tomorrow too!
Click to expand...

Sorry, I don't know how hard it was. I paid a shop to install the lower mounts. I didn't have the time to mess with this.
 
Not only are bad mounts a result of lots of noises but they change your drivetrain geometry which results in vibration under acceleration. Plus one bad mount puts undo stress on all of the other mounts, accelerating their failure and eventually resulting in more necessary repairs. They're so cheap and easy to replace that it's a good idea to get them swapped out of they're bad.
 


You must log in or register to reply here.
Back
Top